1. Field of the Invention
This invention relates to a lock device, and particularly to a lock furnished with a replaceable lock core.
2. Description of the Prior Art
In a conventional cylindrical lock, the inner space of the casing is mounted with an upper tumbler seat and a lower tumbler seat; a plurality of symmetrical tumbler holes are furnished between the upper and lower tumbler seats to be loaded with tumblers and springs respectively; normally, the springs in the tumbler holes will push the front ends of the front tumblers to the positioning edge of the front end of the casing. Since the tumblers are different in length, they can mate with different keys for unlocking; after a correct key is plugged into the cylindrical lock, the unlock grooves on the front end of the cylindrical lock will push the front tumblers to move forwards to an interface between the upper tumbler seat and the lower tumbler seat, i.e., the front tumblers and the rear tumblers are put along a rotary tangent surface; then, a turning and driving plate of the cylindrical key will drive the upper tumbler seat to turn, and a transmission shaft of the upper tumbler seat will drive a driving arm to turn.
In a conventional lock device, the lock lamina or the lock tumblers mounted in a body casing are different in structure, and the key for unlocking the same is also different in structure; therefore, the lock-up function is also different. In the conventional laminated lock structure, the assembling procedures thereof is rather simple aside from the picklock factors; it can obtain a high manufacturing precision without being unlocked with a master key.
In the conventional locks, different locks are substantially different in the structure of their tumblers, i.e., each type of lock has its features; after a given period of being sold, the locking function thereof is subject to being learned or known by other person, and then it is subject to being unlocked easily.
In fact, the locking-up purpose of a lock can be achieved only when the toughness of the structure and the precision of a lock reach a given standard as desired; then, the convenience in use and repair is another consideration to a lock.
The prime object of the present invention is to provide a lock furnished with a replaceable lock core, in which the lock casing of the cylinder-shaped lock device has a cylindrical hole for mounting an inner lock assembly; the cylindrical hole of a sleeve of the inner lock assembly is to be mounted with a control ring and a lock core; the control ring is furnished with two control cylindrical surfaces having different turning direction, i.e., a key inserted to unlock a lock device in one turning direction, or in another turning direction to pull out an inner lock assembly to replace a new lock core.
Another object of the present invention is to provide a lock furnished with a replaceable lock core, in which the lock casing of the lock device may not be removed upon pulling out the inner lock assembly for replacement so as to minimize the cumbersome steps to the related parts.
Still another object of the present invention is to provide a lock furnished with a replaceable lock core, in which the center cylindrical hole of the lock casing in the lock device is for mounting an inner lock assembly; the key of the lock has a key plate, which is furnished with a positioning block; the length of the positioning block is varied with the function of a key, i.e., a key for unlocking the lock, or a key for replacing an inner lock assembly; to replace an inner lock assembly, the key should be used to unlock the lock core before pulling out the inner lock assembly.
A further object of the present invention is to provide a lock furnished with a replaceable lock core, in which a control ring is mounted in the sleeve of the inner lock assembly; a control cylindrical surface of the control ring is furnished with a guide slot for receiving a key; both sides of the guide slot are furnished with two control cylindrical surfaces respectively with different length; normally, the key is turned clockwise, and the positioning block of the key will turn along the control cylindrical surface for unlocking without hindering the retaining relation between he inner lock assembly and the lock casing.
A still further object of the present invention is to provide a lock furnished with a replaceable lock core, in which the control ring of the inner lock assembly has a control cylindrical surface to be used for replacing an inner lock assembly; in that case, a key with a short positioning block; when the lock core is unlocked, the key is turned clockwise, and then the key is turned counter-clockwise so as to have the positioning block moved along the control cylindrical surface of the control ring; when the transmission shaft of the lower tumbler base is turned, the cut slot thereof will move to the lower end of the catch pin; then, the catch pin will release the catching relation between the inner lock assembly and the lock casing as a result of being pushed by a spring; the inner lock assembly will be pulled out upon the key being pulled, and the replacement of a new lock core in the inner lock assembly is done.